<?php
/**
演示
require_once('../libs/classes/page.class.php');
$page=new page(array('total'=>1000,'perpage'=>20));
echo 'mode:1<br>'.$page->show();
echo '<hr>mode:2<br>'.$page->show(2);
echo '<hr>mode:3<br>'.$page->show(3);
echo '<hr>mode:4<br>'.$page->show(4);
echo '<hr>开始AJAX模式:';
$ajaxpage=new page(array('total'=>1000,'perpage'=>20,'ajax'=>'ajax_page','page_name'=>'test'));
echo 'mode:1<br>'.$ajaxpage->show();
*/

class page 
{
	/**
	* config ,public
	*/
	var $page_name="PageNum";//page标签，用来控制url页。比如说xxx.php?PB_page=2中的PB_page
	var $next_page='下一页';//下一页
	var $pre_page='上一页';//上一页
	var $first_page='首页';//'First';//首页
	var $last_page='尾页';//'Last';//尾页
	var $pre_bar='<<';//上一分页条
	var $next_bar='>>';//下一分页条
	var $format_left='[';
	var $format_right=']';
	var $is_ajax=false;//是否支持AJAX分页模式
	var $style='a2'; 
	var $recordcount=0;
	
	/**
	* private
	*
	*/ 
	var $pagebarnum=10;//控制记录条的个数。
	var $totalpage=0;//总页数
	var $ajax_action_name='';//AJAX动作名
	var $nowindex=1;//当前页
	var $url="";//url地址头
	var $offset=0;
	
	/**
	* constructor构造函数
	*
	* @param array $array['total'],$array['perpage'],$array['nowindex'],$array['url'],$array['ajax']...
	*/
	function page($array="")
	{
		if(is_array($array)){
			 if(!array_key_exists('total',$array))$this->error(__FUNCTION__,'need a param of total');
			 $total=intval($array['total']);
			 $this->recordcount=$total;
			 $perpage=(array_key_exists('perpage',$array))?intval($array['perpage']):10;
			 $nowindex=(array_key_exists('nowindex',$array))?intval($array['nowindex']):'';
			 $url=(array_key_exists('url',$array))?$array['url']:'';
			 $style=(array_key_exists('style',$array))?'class='.$array['style']:'';
		}else{
			 $total=$array;
			 $perpage=10;
			 $nowindex='';
			 $url='';
			 $style='class=a2';
		}
		if((!is_int($total))||($total<0))$this->error(__FUNCTION__,$total.' is not a positive integer!');
		if((!is_int($perpage))||($perpage<=0))$this->error(__FUNCTION__,$perpage.' is not a positive integer!');
		if(!empty($array['page_name']))$this->set('page_name',$array['page_name']);//设置pagename
		$this->_set_nowindex($nowindex);//设置当前页
		$this->_set_url($url);//设置链接地址
		$this->totalpage=ceil($total/$perpage);
		$this->offset=($this->nowindex-1)*$perpage;
		if(!empty($array['ajax']))$this->open_ajax($array['ajax']);//打开AJAX模式

	}
	/**
	* 设定类中指定变量名的值，如果改变量不属于这个类，将throw一个exception
	*
	* @param string $var
	* @param string $value
	*/
	function set($var,$value)
	{
		if(in_array($var,get_object_vars($this)))
			 $this->$var=$value;
		else {
		   $this->error(__FUNCTION__,$var." does not belong to PB_Page!");
		}
	}
	/**
	* 打开倒AJAX模式
	*
	* @param string $action 默认ajax触发的动作。
	*/
	function open_ajax($action)
	{
		$this->is_ajax=true;
		$this->ajax_action_name=$action;
	}
	/**
	* 获取显示"下一页"的代码
	* 
	* @param string $style
	* @return string
	*/
	function next_page($style='')
	{
		if($this->nowindex<$this->totalpage){
		   return $this->_get_link($this->_get_url($this->nowindex+1),$this->next_page,$style);
		}
		return '<span  class=disabled>'.$this->next_page.'</span>';
	}
	
	/**
	* 获取显示“上一页”的代码
	*
	* @param string $style
	* @return string
	*/
	function pre_page($style='')
	{
		if($this->nowindex>1){
		   return $this->_get_link($this->_get_url($this->nowindex-1),$this->pre_page,$style);
		}
		return '<span class=disabled>'.$this->pre_page.'</span>';
	}
	
	/**
	* 获取显示“首页”的代码
	*
	* @return string
	*/
	function first_page($style='')
	{
		if($this->nowindex==1){
			  return '<span class=disabled>'.$this->first_page.'</span>';
		}
		return $this->_get_link($this->_get_url(1),$this->first_page,$style);
	}
	
	/**
	* 获取显示“尾页”的代码
	*
	* @return string
	*/
	function last_page($style='')
	{
		if($this->nowindex==$this->totalpage){
			  return '<span class=disabled>'.$this->last_page.'</span>';
		}
		return $this->_get_link($this->_get_url($this->totalpage),$this->last_page,$style);
		}
		
		function nowbar($style='',$nowindex_style='')
		{
		$plus=ceil($this->pagebarnum/2);
		if($this->pagebarnum-$plus+$this->nowindex>$this->totalpage)$plus=($this->pagebarnum-$this->totalpage+$this->nowindex);
		$begin=$this->nowindex-$plus+1;
		$begin=($begin>=1)?$begin:1;
		$return='';
		for($i=$begin;$i<$begin+$this->pagebarnum;$i++)
		{
		   if($i<=$this->totalpage){
			if($i!=$this->nowindex)
				$return.=$this->_get_text($this->_get_link($this->_get_url($i),$i,$style));
			else 
				$return.=$this->_get_text('<span class=current>'.$i.'</span>');
		   }else{
			break;
		   }
		   $return.="\n";
		}
		unset($begin);
		return $return;
	}
	/**
	* 获取显示跳转按钮的代码
	*
	* @return string
	*/
	function select($url)
	{
		$pageurl=$this->url;
		//如果是使用AJAX模式
		if($this->is_ajax) {
			//$return= ' <a '.$style.' href="javascript:'.$this->ajax_action_name.'(\''.$url.'\')">'.$text.'</a> ';
			$return='<select name="PB_Page_Select" onchange="javascript:'.$this->ajax_action_name.'(\''.$pageurl.'\'+ this.value)">';
		} else {
			$return="<select name='PB_Page_Select' onchange=\"javascript:location.href='".$pageurl."'+ this.value;\" >";
		}
		
		
		
		for($i=1;$i<=$this->totalpage;$i++)
		{
		   if($i==$this->nowindex){
			$return.='<option value='.$i.' selected>'.$i.'</option>';
		   }else{
			$return.='<option value='.$i.'>'.$i.'</option>';
		   }
		}
		unset($i);
		$return.='</select>';
		return $return;
	}
	
	/**
	* 获取mysql 语句中limit需要的值
	*
	* @return string
	*/
	function offset()
	{
		return $this->offset;
	}
	
	/**
	* 控制分页显示风格（你可以增加相应的风格）
	*
	* @param int $mode
	* @return string
	*/
	function show($mode=1,$url='')
	{
		switch ($mode)
		{
		   case '1':
			$this->next_page;//='下一页';
			$this->pre_page;//='上一页';
			return $this->pre_page().' '.$this->nowbar().$this->next_page().' 第'.$this->select($url).'页';
			break;
		   case '2':
			$url=GetUrl();
			$this->next_page;//=' 下一页 ';
			$this->pre_page;//=' 上一页 ';
			$this->first_page;//=' 首页 ';
			$this->last_page;//=' 尾页 ';
			
			return '[当前:'.$this->nowindex.'/'.$this->totalpage.' 共:'.$this->recordcount.'条] '.$this->first_page($this->style).$this->pre_page($this->style).$this->next_page($this->style).$this->last_page($this->style).'第'.$this->select($url).'页';
			break;
		   case '3':
			$this->next_page;//='下一页';
			$this->pre_page;//='上一页';
			$this->first_page;//='首页';
			$this->last_page;//='尾页';
			return $this->first_page().$this->pre_page().$this->next_page().$this->last_page();
			break;
		   case '4':
		   
			$this->next_page;//='下一页';
			$this->pre_page;//='上一页';
			$this->first_page;//='首页';
			$this->last_page;//='尾页';
			return $this->pre_page().' '.$this->nowbar().$this->next_page();
			break;
		   case '5':
			return $this->pre_bar().$this->pre_page().$this->nowbar().$this->next_page().$this->next_bar();
			break;
		}
	
	}
	/*----------------private function (私有方法)-----------------------------------------------------------*/
	/**
	* 设置url头地址
	* @param: String $url
	* @return boolean
	*/
	function _set_url($url="")
	{
		if(!empty($url)){
			  //手动设置
		   $this->url=$url.((stristr($url,'?'))?'&':'?').$this->page_name."=";
		}else{
			  //自动获取
		   if(empty($_SERVER['QUERY_STRING'])){
			   //不存在QUERY_STRING时
			$this->url=$_SERVER['REQUEST_URI']."?".$this->page_name."=";
		   }else{
			   //
			if(stristr($_SERVER['QUERY_STRING'],$this->page_name.'=')){
				//地址存在页面参数
			 $this->url=str_replace($this->page_name.'='.$this->nowindex,'',$_SERVER['REQUEST_URI']);
			 $last=$this->url[strlen($this->url)-1];
			 if($last=='?'||$last=='&'){
				 $this->url.=$this->page_name."=";
			 }else{
				 $this->url.='&'.$this->page_name."=";
			 }
			}else{
				//
			 $this->url=$_SERVER['REQUEST_URI'].'&'.$this->page_name.'=';
			}//end if    
		   }//end if
		}//end if
	}
	
	
	
	/**
	* 设置当前页面
	*
	*/
	function _set_nowindex($nowindex)
	{
		if(empty($nowindex)){
		   //系统获取
		   
		   if(isset($_GET[$this->page_name])){
			$this->nowindex=intval($_GET[$this->page_name]);
		   }
		}else{
			  //手动设置
		   $this->nowindex=intval($nowindex);
		}
	}
	
	/**
	* 为指定的页面返回地址值
	*
	* @param int $pageno
	* @return string $url
	*/
	function _get_url($pageno=1)
	{
		return $this->url.$pageno;
	}
	
	/**
	* 获取分页显示文字，比如说默认情况下_get_text('<a href="">1</a>')将返回[<a href="">1</a>]
	*
	* @param String $str
	* @return string $url
	*/ 
	function _get_text($str)
	{
		//return $this->format_left.$str.$this->format_right;
		return $str;
	}
	
	/**
	   * 获取链接地址
	*/
	function _get_link($url,$text,$style){
	
		$style='class='.$this->style;
		
		if($this->is_ajax){
			  //如果是使用AJAX模式
		   return '<a '.$style.' href="javascript:'.$this->ajax_action_name.'(\''.$url.'\')">'.$text.'</a>';
		}else{
		   return '<a '.$style.' href="'.$url.'">'.$text.'</a>';
		}
	}
	/**
	   * 出错处理方式
	*/
	function error($function,$errormsg)
	{
		 die('Error in file <b>'.__FILE__.'</b> ,Function <b>'.$function.'()</b> :'.$errormsg);
	}
}

?>
